Modine's Amp Dawg AMP057 has the lowest figures of any electric garage heater we could tie to a distance. Modine's sell sheet gives the 5.7 kW unit 41.7 dBA at 15 feet, 45 at 10 feet and 49.8 at 5 feet from the front, and it hangs from a rail 1 inch below the ceiling with nothing to vent. If gas is already piped to the garage, Reznor's technical sheet lists its UDXC heaters in sizes 30, 45 and 60 at 40 dBa at 15 feet.
Those two answers stay on separate lines, and so does every other kind of figure on this page. A gas heater runs a venter motor and a burner as well as its fan, neither maker names a stage or a test room, and Modine's own sound sheet says its values "should only be used to compare noise levels of similar types of equipment at the same distance and in the same environment." So we rank electric against electric and gas against gas, one distance at a time, and keep the plain-decibel figures, one upper limit and a fanless "0 dB" claim apart from both. The second half of the page covers what a garage adds: how high each heater must hang, what the gas manuals say about venting and carbon monoxide, and what every manual rules out near gasoline, solvents and wet floors.
Our picks are listed above, with full specifications for each.
Modine prints the most. Its 2026 Amp Dawg sell sheet gives both electric sizes a figure at 5, 10 and 15 feet from the front. A separate sound pressure sheet from April 2024 covers the gas Hot Dawg HD and HDS: sizes 30 to 75 at 5 feet, and sizes 100 and 125 at 10 and 15 feet.
Reznor prints a "Sound level @ 15 feet" in dBa for every size of its UDXC gas heater and a "Sound level @ 10 feet" for its compact electric EUHC, each in the model's technical specifications. Neither row names a stage or says which side of the heater the meter faced.
Heat Storm prints figures with no distance. The page for its 6000-watt garage heater says "Sound: 45-49 decibels" while the manual says "Decibles: 39", and its infrared Tradesman heaters claim 0 dB.
NewAir prints "≤55 db" in the manual for its NGH500GA00, a 4,800 watt heater that plugs into a 30 amp, 240 V outlet, and nothing on the pages or in the manuals for its hardwired G73 and NGH1K6WH00.
The other makers we read sell on words or print nothing about noise. Dr. Infrared says the fans in its DR-975 and DR-910F garage heaters give "maximum air flow with minimum turbulence and noise". Mr. Heater writes that a year-round garage workspace needs "a safe quiet and reliable heat source" and offers its Big Maxx gas heaters as one, and it says its propane forced air heaters run "50% quieter than standard forced air heaters", with no figure behind either line. King's submittals for its KB, KBP and GH garage heaters, Comfort Zone's ceiling-mounted heaters, and the Fahrenheat FUH and Qmark MUH pages from Marley Engineered Products print no noise figure at all.
Electric heaters at 5, 10 and 15 feet
Three electric heaters carry an A-weighted figure tied to a distance, and 10 feet is the one distance all three share:
- Modine Amp Dawg AMP057, 5.7 kW: 45 dBA.
- Modine Amp Dawg AMP090, 9.0 kW: 49 dBA.
- Reznor EUHC 3 and 5, 3 or 5 kW: 58 dBa.
Modine adds the other two distances: 49.8 dBA at 5 feet and 41.7 at 15 for the AMP057, and 53.7 and 46.1 for the AMP090. That is a drop of about 8 dB between 5 and 15 feet on both heaters, which is why a ceiling heater's figure means little without its distance, and why we never put a 5 foot figure beside a 15 foot one. Reznor's 58 dBa is 13 above the AMP057 at the same 10 feet, a gap wide enough that we rank the EUHC below both Amp Dawgs even though the figures come from different makers. Reznor's own table runs in an odd order, with 67 dBa for its 7 and 10 kW cabinet and 56 for the 20 kW, which turns a 16 inch fan at 1,050 rpm.
Modine's noise documents disagree once. Its 2024 electric heating brochure says "Quiet operation as low as 40dBA at 15 ft.", while the lowest figure at 15 feet on the 2026 sell sheet is the AMP057's 41.7. We rank on the sell sheet, which gives each size a figure at each distance.
Neither Modine figure names a stage, and two settings change what the heater does. The AMP090 has two stages, and its manual says the AMP057's capacity, airflow, temperature rise and throw "also correspond to low stage of AMP090"; Modine prints no sound figure for that low stage. Wired to a single-stage thermostat, with a dipswitch set to match, the AMP090 starts low and moves to high only when the call for heat lasts more than 10 minutes. A dipswitch can also run the AMP057's fan at high speed, for the AMP090's airflow and throw with a temperature rise 10°F lower, and Modine prints no figure for that setting either.
Gas heaters: Reznor at 15 feet, Modine mostly at 5
Reznor's UDXC rows, all at 15 feet:
- UDXC 30, 45 and 60: 40 dBa.
- UDXC 75: 49 dBa.
- UDXC 100: 54 dBa.
- UDXC 125: 55 dBa.
Modine's rows for the Hot Dawg HD and HDS, from one sheet:
- At 5 feet: 53 dBA for the 30, 57 for the 45, and 55 for the 60 and 75.
- At 10 and 15 feet: 50 and 48 dBA for the 100, and 58 and 57 for the 125.
The two makers meet at one distance only in their larger sizes. At 15 feet Modine's HD100 lists 48 dBA against 54 for Reznor's UDXC 100, and the HD125 lists 57 against 55 for the UDXC 125. The 6 dB at the 100 size is the clearest difference between them; 2 dB at the 125 size is small enough to come from two makers' test rooms, so we read that pair as level.
For the smaller sizes the makers chose different distances, and nothing lines Reznor's 30, 45 and 60 up against Modine's 30 to 75. They appear as two picks: the UDXC 60, the largest heater at Reznor's 40 dBa, and the HD30, the lowest Hot Dawg figure at 5 feet. Neither maker gives a figure for low fire, either. Reznor lists low-fire output for the UDXC 60 and up with its optional two-stage valve, and Modine offers two-stage controls from the HD75 up.
Plain decibels, an upper limit and a 0 dB claim
Heat Storm's HS-6000-GC is the one fan heater among the picks whose figure comes with no distance, and its two documents disagree: "Sound: 45-49 decibels" on the product page, "Decibles: 39" in the manual. We show both on its card and rank it against neither group, because a number with no distance cannot be set beside the AMP057's 45 dBA at 10 feet. The manual is clearer about the heater's modes than its sound: Low runs at 50% power, High at 100%, and Auto at full power until the room is within 2 degrees of the set temperature, then at 50%.
NewAir's "≤55 db" for the NGH500GA00 is an upper limit, not an exact value, so it sits on its own as well. Its manual names a sound no other manual here mentions: "Usage on outlets above 220 volts may cause a slight whistling sound due to the higher fan speed." Since the same manual asks for a 208 to 240 volt outlet, a 240 volt garage circuit is above that 220 volt line.
An infrared heater has no fan to hear. Heat Storm's compact Tradesman 6000 lists "CFM: 0" and "Decibels: 0" in its manual, and Reznor describes its 1.5 kW RIEH infrared heater as "Silent operation; no fan or moving parts" without a figure. 0 dB is the threshold of hearing, not a reading, so the Tradesman ranks after every heater with a figure, even though nothing in it turns. Heat Storm says it warms people and objects directly rather than the air around them.
What runs before and after the heat
A figure describes a heater while it runs, and the manuals also describe what you hear on either side of that:
- Reznor UDXC: on a call for heat the venter motor starts and runs a 20 second prepurge, the burner lights, and the fan starts 30 seconds after the gas valve opens. When the thermostat is satisfied the venter runs a 45 second post-purge, and the fan stops after its selected off delay. Reznor's page says both motors are "Vibration/noise isolated".
- Modine Hot Dawg: the power exhauster starts first and runs a purge period before the spark, and Modine's page says the in-shot burners give a "low sound level on flame ignition/extinction".
- Modine Amp Dawg: the fan starts shortly after the thermostat calls for heat, and once the thermostat is satisfied it keeps running through a cooldown period to clear the heat left in the elements.
- Heat Storm HS-6000-GC: no air for the first 15 seconds while its elements heat, and after it is switched off, "The heater will run up to 12 minutes to cool the internal components." The manual adds that "The fan will turn on and off to circulate air" while the heater checks the room temperature.
- NewAir NGH500GA00: the whistle above 220 volts.
- Dr. Infrared DR-975: "small cracking sounds" the first time it is switched on, which the manual calls normal.
Venting and carbon monoxide in the gas manuals
The first item in the warnings of Modine's Hot Dawg manual is "Gas fired heating equipment must be vented - do not operate unvented." Reznor's manual explains why: a burner that does not get enough combustion air produces "carbon monoxide, a poisonous gas that can cause death", and "Safe operation of indirect-fired gas burning equipment requires a properly operating vent system that vents all flue products to the outside atmosphere."
Both makers' heaters are power-vented, with a motor that pushes the flue gases out through a pipe. Modine vents the HD30 to HD75 through a 3 inch pipe, horizontally or vertically, and says not to use PVC or other plastic pipe, nor to place a heater where its flue products can be drawn into windows or fresh air intakes. Reznor allows a Category I vertical vent or a Category III vent for the UDXC 30 to 100 in a home. Mr. Heater's page lists "Category 1 vertical, category 3 horizontal venting" for the Big Maxx. Reznor's homeowner brochure adds that installation must be done by a licensed or certified HVAC contractor.
The certification is narrower than the words garage heater suggest. Modine and Reznor list these heaters as utility heaters for non-living spaces attached to or part of a home, "not intended to be the primary source of heat in residential applications", and Reznor adds "or to be used in sleeping quarters". A room over the garage where someone lives is not a use either maker certifies.
The US Consumer Product Safety Commission says CO alarms belong on every level of a home and outside sleeping areas, and that a professional should inspect fuel-burning heating systems, flues and vents every year. It also lists how things go wrong: "CO poisoning can occur if heating systems are installed incorrectly, poorly maintained, have defective or blocked venting systems or are misused."
How high each heater hangs, and the space around it
The makers' lowest mounting heights, measured to the bottom of the heater, with the clearances each manual sets:
- Modine Amp Dawg: 6 feet in the US, with 1 inch at the top and sides, 12 inches below, and 12 inches behind (18 preferred for service).
- Reznor EUHC: 6 feet, with 2 inches at the top, 7 behind, 4 at the sides and 36 in front of the outlet.
- Reznor UDXC: 5 feet, with 1 inch at the top and on the non-access side, 6 at the flue connector, and 18 on the access side and behind the fan motor. Reznor says a unit should generally hang 8 to 12 feet up.
- Modine Hot Dawg: 5 feet in residential applications and 7 feet in garages unless the unit is guarded, with 1 inch at the top, bottom and sides and 18 inches behind.
- Heat Storm HS-6000-GC: 5 feet 10 inches, with 4 inches from nearby walls and the ceiling.
- Heat Storm compact Tradesman: 70 inches, with 23 inches from nearby walls and the ceiling.
- Dr. Infrared DR-975: 6 feet, 1 foot from adjacent surfaces and 4.5 inches from the back wall.
- Mr. Heater Big Maxx MHU50: "Minimum 8 ft clearance from floor to base of heater required".
The Hot Dawg's two heights are worth reading twice. Its manual gives 5 feet for residential applications and 7 feet in garages, so in a home garage we would plan on 7 feet unless the installer reads it otherwise. The Amp Dawg needs only an inch above it, which is the point of what Modine calls a "Low-profile design" that "maximizes overhead garage space".
Where you stand decides which row applies to you. Under a heater hung at 7 feet, the head of anyone standing beneath it is far closer than 5 feet, the shortest distance any maker here prints.
Gasoline, solvents and wet floors
Every manual here assumes the garage holds things a heater should not meet. Modine's Amp Dawg and Hot Dawg manuals both warn that "The use and storage of gasoline or other flammable vapors and liquids in open containers in the vicinity of this appliance is hazardous", and that appliances "must not be installed where they may be exposed to a potentially explosive or flammable atmosphere". Heat Storm's Tradesman manual lists "Locations with gasoline, paint, or flammable liquids" among the places not to use it, and NewAir's manual says the same of areas where gasoline, paint or flammable liquids are used or stored.
The gas manuals add solvents. Modine says not to locate any gas-fired unit where "chlorinated, halogenated, or acid vapors" are present, because they cause premature heat exchanger failure. Reznor names where those vapors come from: halogenated hydrocarbons are "used in refrigerants, cleaning agents, and solvents", they form hydrochloric acid in a flame, and "An outside air supply MUST BE provided to the burner whenever the presence of these compounds is suspected." That is the case for separated combustion, which takes its combustion air from outdoors: Modine sells it as the Hot Dawg HDS, which shares the HD's sound figures, and Reznor as kit SC1 for the UDXC.
Water is the last rule. Modine says not to install the Amp Dawg in "outdoor, wet, or moist locations", nor a Hot Dawg where its ignition system "is exposed to water spray, rain, or dripping water", and Reznor says the same of the EUHC. NewAir's manual is the bluntest about garages: "Do not use near sinks, swimming pools or other damp areas such as flooded basements, garages, etc." Heat Storm rules out "Wet or moist locations" for the Tradesman, though it calls the heater weather resistant.
How we chose
We looked for heaters sold in the US to warm a cold garage for hours: 240 V electric unit heaters for a ceiling or wall, 240 V infrared heaters, and vented gas or propane unit heaters. For Modine, Reznor, Heat Storm, NewAir, Dr. Infrared, King, Comfort Zone, Mr. Heater and Marley's Fahrenheat and Qmark lines, we read the US product pages and, where the maker posts them, the sell sheets, technical specifications and installation manuals on October 13, 2026, and copied every figure with its unit and distance. Cadet's garage and workshop heater pages load their specifications by script, and we could not read a figure on them. We ranked figures only against figures of the same fuel, weighting and distance, put heaters with a distance-tied figure above those without, and kept the plain-decibel figures, the one upper limit and the 0 dB claim apart. Modine and Reznor sell through distributors and publish no prices, so their cards show none; the other prices are the makers' own on October 13, 2026.
We did not measure any of these garage heaters; each decibel figure is copied from a Modine, Reznor, Heat Storm or NewAir sheet, page or manual, and each mounting, venting and clearance rule from the maker's own instructions.
